Costructing on a mine tailings site

[GilBor]

I am trying to decide about the purchase of a land property (5000 M^2)
located in an area used by a mining company to dump mining tailings
about 50 yrs ago. I hired a soil engineer to help me make the decision
and am seeking farther advice (second opinion) from the experts in
this forum. Details follow.

The property is located in Guanajuato (Mexico). The tailings were
layered on a slope of a hill, forming a big flat terrace sized about
200 by 100 meter. The soil is mostly fine powder, with some thin layer
of top soil (max 30cm) with some vegetation (trees up to 3 meters
high). I intend to use this land to construct 3 brick houses (for
myself and 2 friends). A soil engineer from a nearby university, who
also works as a consultant for foundations, looked at it, took some
superficial samples (the owners wouldnt let us make holes deeper then
1 meter) and is supposed to send me a lab report within several days
with recommendations for foundations. He said I will probably need to
build the house on a concrete slab located on top of a treated layer
of imported material (soil moved from some other site, i guess).

Specific questions:

1. Is it reasonable to build a (modest) house on such a soil? I mean,
can you make not-too-expensive foundations that will support the house
for many yrs?

2. In case the answer is yes, is the aformentioned method the right one
or I should look into other methods?

 

[sc]

Why wont the owner let you do some deeper bore holes? Is something being hidden from you?

Tailings are generally placed by dumping, minor leveling and minimum compaction, hence they can vary greatly in bearing capacity and consistency. You really need the deeper bore holes and a range of insitu testing backed up by lab tests to show how stable the tailings dump is as well as whether or not it is contaminated tailings (fairly important for your health).

As the site is a fill site I would look towards using a pier and beam slab system to penetrate the depth of fill (unless the soil tests/lab report show that it is very stable).

Regards
sc

 

[Robert168]

In addition to the sampling and investigation of the tailing for the design of foundation, I think the stablility of the the tailing at a large area or as a whole should be studied.

 

[Focht3]

I would suggest that you check out the comments in thread256-76595 before you post to this message thread -



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